It is desirable to provide an animal feed in the form of a formulated ration that contains desired and necessary nutrients. The preferred presentation of the formulated ration is in the form of a compact pellet. Such pellets are convenient for the operator to provide to the animal, and are palatable to the animal.
Often, it is desired to provide a high-fat animal feed in order to supply the animal with optimum nutritional energy. It is difficult, however, to incorporate high levels of fat into a pelletized formula. Specifically, when an animal feed pellet is formulated with a fat level greater than about 10% by weight, the intrapellet cohesive strength is substantially weakened, thereby making the pellet more likely to fracture and to create dust and wastage.
In recognition of this problem, the prior art has provided numerous pellet binders in an attempt to improve the intrapellet cohesive strength of animal feed pellets. For instance, the use of inorganic binders composed of calcium salts is taught in U.S. Pat. Nos. 4,988,520, 5,714,184 teaches the use of the digest of wood chips with soda ash as a binder in animal feeds. Condensed soybean solubles are used as the binder in animal feed blocks in U.S. Pat. Nos. 4,349,578, and 5,871,802 teaches the use of liquid by-products such as corn steep liquor and condensed distillery solubles as binders in animal feed pellets. Wheat gluten is taught as the binder for animal feed pellets in U.S. Pat. No. 5,102,671, and hydrolyzed starch is used as the binder in U.S. Pat. No. 4,048,268 for extruded animal feeds made to contain antibiotics. Another document, U.S. Pat. No. 4,976,977, teaches a combination of clay and molasses as a pelleting agent for animal feed. Collagen, an animal-derived binder, also is sometimes used as a binder.
For various reasons, the binders taught in the foregoing references are less than satisfactory. Generally, the binders taught in the foregoing references allow modest levels of fat to be incorporated into the pelleted product, but such binders are not suitable for higher fat animal feeds. Certain of the foregoing binders suffer from other drawbacks. For instance, recent outbreaks of transmissible spongiform encephalopathies, such as Bovine Spongiform Encephalopathy (commonly known as “mad cow disease”) have received concerns about the safety of use of animal-derived products such as collagen in feedstocks for other animals.
At present, the most common method for providing high-fat animal feeds is to formulate a low-fat feed and to spray a vegetable fat onto the feed. However, although fat levels can be increased using the foregoing technique, other difficulties arise. For instance, the fat-covered feed is difficult to handle and transport. For these and other reasons, fat-sprayed feeds are generally unsatisfactory.
In light of the drawbacks inherent in the foregoing known binders and feeds, it is a general object of the invention to provide an animal feed that incorporates a satisfactory binder.